It contains a variety of trace and body fossils, preserved in sandy fluvial channel deposits and overbank units.

Dinosaur remains are fragmentary, but include Triceratops, Tyrannosaurus, dromaeosaurids, Paronychodon, Ricardoestesia, Edmontosaurus, Edmontonia, Ankylosaurus, and Pachycephalosaurus.

The local K-T boundary is contained within a sandy channel deposit made up of stacked bars.

[2] The Ferris Formation is up to 2,000 metres (6,600 ft) thick in the Hanna Basin and represents a rapid accumulation of predominantly fine-grained sediment on a broad delta.

The delta previously fed the deepwater Lewis Shale and shallow marine Fox Hills Formation.